[PATCH 2/4] EDAC/amd64: Remove NUM_CONTROLLERS macro

Avadhut Naik
2025-10-13T17:37:17Z

Currently, the NUM_CONTROLLERS macro is only used to statically allocate
the csels array of struct chip_select in struct amd64_pvt.

The size of this array, however, will never exceed the number of UMCs on
the SOC. Since, max_mcs variable in struct amd64_pvt already stores the
number of UMCs on the SOC, the macro can be removed and the static array
can be dynamically allocated instead.

The max_mcs variable and the csels array are used for legacy systems too.
These systems have a max of 2 controllers (DCTs). Since the default value
of max_mcs, set in per_family_init(), is 2, these legacy system are also
covered by this change.

Signed-off-by: Avadhut Naik <avadhut.naik@amd.com>
---
drivers/edac/amd64_edac.c | 5 +++++
drivers/edac/amd64_edac.h | 5 ++---
2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 886ad075d222..2391f3469961 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -3732,6 +3732,7 @@ static void hw_info_put(struct amd64_pvt *pvt)
pci_dev_put(pvt->F1);
pci_dev_put(pvt->F2);
kfree(pvt->umc);
+ kfree(pvt->csels);
}

static struct low_ops umc_ops = {
@@ -3915,6 +3916,10 @@ static int per_family_init(struct amd64_pvt *pvt)
scnprintf(pvt->ctl_name, sizeof(pvt->ctl_name), "F%02Xh_M%02Xh",
pvt->fam, pvt->model);

+ pvt->csels = kcalloc(pvt->max_mcs, sizeof(*pvt->csels), GFP_KERNEL);
+ if (!pvt->csels)
+ return -ENOMEM;
+
return 0;
}

diff --git a/drivers/edac/amd64_edac.h b/drivers/edac/amd64_edac.h
index bb6cf4b1ab77..5f61631c8a7d 100644
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -96,7 +96,6 @@
/* Hardware limit on ChipSelect rows per MC and processors per system */
#define NUM_CHIPSELECTS 8
#define DRAM_RANGES 8
-#define NUM_CONTROLLERS 16

#define ON true
#define OFF false
@@ -347,8 +346,8 @@ struct amd64_pvt {
u32 dbam0; /* DRAM Base Address Mapping reg for DCT0 */
u32 dbam1; /* DRAM Base Address Mapping reg for DCT1 */

- /* one for each DCT/UMC */
- struct chip_select csels[NUM_CONTROLLERS];
+ /* Allocate one for each DCT/UMC */
+ struct chip_select *csels;

/* DRAM base and limit pairs F1x[78,70,68,60,58,50,48,40] */
struct dram_range ranges[DRAM_RANGES];
--
2.43.0